There are many methods to produce AlN powder. Commercial production of AlN uses either the carbothermal reduction of Al.sub.2 O.sub.3 or the nitridation of aluminum powder by a fluidized bed. The direct nitridation of aluminum powder occurs between 1300.degree. C. and 1600.degree. C. with a residence time of 2-3 seconds. The primary interest in AlN is the unusual property combination of high terminal conductivity (200 W/m-K) with a high electrical resistivity (&gt;10.sup.14 .OMEGA.-cm). The AlN material has distinct advantages for thermal management applications in multilayer chips. Other potential applications are for high conductivity refractory materials for investment casting shell systems, composite particulate reinforcement or advanced spark plug materials.
There are many methods to produce AlN powder. One disadvantage of commercial production of AlN is that the process involves complicated multiple steps, which sometimes produces hazardous by-products.
It is therefore a principal object of this invention to product AlN powder through a direct conversion process from pure metal to a reaction product.
A further object of this invention is to produce AlN powder with a simple apparatus with the incorporation of a melt system on top of a typical commercial plasma gun.
A further object of this invention is to produce AlN powder wherein no hazardous by-products will be created.
A still further object of this invention is to create AlN powder by feeding molten metal or alloys into a D.C. arc plasma torch to atomize the metal into droplets, and to simultaneously react the liquid droplets with the ionized plasma to produce a fine reacted AlN powder.
These and other objects will be apparent to those skilled in the art.